The program will examine the ways in which thinking depends on the incentives to which a person relates himself, effect depends on the status of his relationships to incentives, and his experiential response to his life situation is related to various coping responses. More specifically, the program aims to study (a) the Dependency of moment-to- moment changes in a subject's ideational stream on the joint effects of his incentive commitments and of cues related to them, (b) the dependency of his affective state (including especially depression and apathy) and mental content (thematic content, directed versus undirected (respondent or fantasy) content, etc.) on the variety, value, and attainability of incentives, and (c) the dependency of spontaneous problem-solving thought, behavioral disturbances, alterations of his life situation, and use of drugs (especially alcohol) on the incentive features of his life situation and on the forms and content of his thought. All of these elements are linked together functionally by a theory now refined and filled out. The investigators will track each of 100 subjects over nine months with a method for sampling subjects' stream of reportable ideation (thought-sampling), interviews, and questionnaires administered repeatedly. The interviews and questionnaires will provide information on subjects' changing commitments to incentives, changing affective tone, and major actions directed at their life situations. The motivational and life- situational variables are"real-life" subject variables but the form, content, and responsiveness of each subject's mentation are studied in the laboratory through the controlled presentation of stimuli and concurrent monitoring of mental content. In order to explore the generality of the findings and to help adapt the methods progressively to populations most in need of help, the study will focus successively on college students, noncollege adults, and subjects who have episodic experiences with depression or heavy use of alcohol.